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-rw-r--r--fs/file_table.c108
-rw-r--r--fs/super.c18
-rw-r--r--include/linux/fs.h7
3 files changed, 115 insertions, 18 deletions
diff --git a/fs/file_table.c b/fs/file_table.c
index 6f0e62ecfddd..a04bdd81c11c 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -20,7 +20,9 @@
#include <linux/cdev.h>
#include <linux/fsnotify.h>
#include <linux/sysctl.h>
+#include <linux/lglock.h>
#include <linux/percpu_counter.h>
+#include <linux/percpu.h>
#include <linux/ima.h>
#include <asm/atomic.h>
@@ -32,7 +34,8 @@ struct files_stat_struct files_stat = {
.max_files = NR_FILE
};
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(files_lock);
+DECLARE_LGLOCK(files_lglock);
+DEFINE_LGLOCK(files_lglock);
/* SLAB cache for file structures */
static struct kmem_cache *filp_cachep __read_mostly;
@@ -336,30 +339,98 @@ void put_filp(struct file *file)
}
}
+static inline int file_list_cpu(struct file *file)
+{
+#ifdef CONFIG_SMP
+ return file->f_sb_list_cpu;
+#else
+ return smp_processor_id();
+#endif
+}
+
+/* helper for file_sb_list_add to reduce ifdefs */
+static inline void __file_sb_list_add(struct file *file, struct super_block *sb)
+{
+ struct list_head *list;
+#ifdef CONFIG_SMP
+ int cpu;
+ cpu = smp_processor_id();
+ file->f_sb_list_cpu = cpu;
+ list = per_cpu_ptr(sb->s_files, cpu);
+#else
+ list = &sb->s_files;
+#endif
+ list_add(&file->f_u.fu_list, list);
+}
+
+/**
+ * file_sb_list_add - add a file to the sb's file list
+ * @file: file to add
+ * @sb: sb to add it to
+ *
+ * Use this function to associate a file with the superblock of the inode it
+ * refers to.
+ */
void file_sb_list_add(struct file *file, struct super_block *sb)
{
- spin_lock(&files_lock);
- BUG_ON(!list_empty(&file->f_u.fu_list));
- list_add(&file->f_u.fu_list, &sb->s_files);
- spin_unlock(&files_lock);
+ lg_local_lock(files_lglock);
+ __file_sb_list_add(file, sb);
+ lg_local_unlock(files_lglock);
}
+/**
+ * file_sb_list_del - remove a file from the sb's file list
+ * @file: file to remove
+ * @sb: sb to remove it from
+ *
+ * Use this function to remove a file from its superblock.
+ */
void file_sb_list_del(struct file *file)
{
if (!list_empty(&file->f_u.fu_list)) {
- spin_lock(&files_lock);
+ lg_local_lock_cpu(files_lglock, file_list_cpu(file));
list_del_init(&file->f_u.fu_list);
- spin_unlock(&files_lock);
+ lg_local_unlock_cpu(files_lglock, file_list_cpu(file));
}
}
+#ifdef CONFIG_SMP
+
+/*
+ * These macros iterate all files on all CPUs for a given superblock.
+ * files_lglock must be held globally.
+ */
+#define do_file_list_for_each_entry(__sb, __file) \
+{ \
+ int i; \
+ for_each_possible_cpu(i) { \
+ struct list_head *list; \
+ list = per_cpu_ptr((__sb)->s_files, i); \
+ list_for_each_entry((__file), list, f_u.fu_list)
+
+#define while_file_list_for_each_entry \
+ } \
+}
+
+#else
+
+#define do_file_list_for_each_entry(__sb, __file) \
+{ \
+ struct list_head *list; \
+ list = &(sb)->s_files; \
+ list_for_each_entry((__file), list, f_u.fu_list)
+
+#define while_file_list_for_each_entry \
+}
+
+#endif
+
int fs_may_remount_ro(struct super_block *sb)
{
struct file *file;
-
/* Check that no files are currently opened for writing. */
- spin_lock(&files_lock);
- list_for_each_entry(file, &sb->s_files, f_u.fu_list) {
+ lg_global_lock(files_lglock);
+ do_file_list_for_each_entry(sb, file) {
struct inode *inode = file->f_path.dentry->d_inode;
/* File with pending delete? */
@@ -369,11 +440,11 @@ int fs_may_remount_ro(struct super_block *sb)
/* Writeable file? */
if (S_ISREG(inode->i_mode) && (file->f_mode & FMODE_WRITE))
goto too_bad;
- }
- spin_unlock(&files_lock);
+ } while_file_list_for_each_entry;
+ lg_global_unlock(files_lglock);
return 1; /* Tis' cool bro. */
too_bad:
- spin_unlock(&files_lock);
+ lg_global_unlock(files_lglock);
return 0;
}
@@ -389,8 +460,8 @@ void mark_files_ro(struct super_block *sb)
struct file *f;
retry:
- spin_lock(&files_lock);
- list_for_each_entry(f, &sb->s_files, f_u.fu_list) {
+ lg_global_lock(files_lglock);
+ do_file_list_for_each_entry(sb, f) {
struct vfsmount *mnt;
if (!S_ISREG(f->f_path.dentry->d_inode->i_mode))
continue;
@@ -406,12 +477,12 @@ retry:
file_release_write(f);
mnt = mntget(f->f_path.mnt);
/* This can sleep, so we can't hold the spinlock. */
- spin_unlock(&files_lock);
+ lg_global_unlock(files_lglock);
mnt_drop_write(mnt);
mntput(mnt);
goto retry;
- }
- spin_unlock(&files_lock);
+ } while_file_list_for_each_entry;
+ lg_global_unlock(files_lglock);
}
void __init files_init(unsigned long mempages)
@@ -431,5 +502,6 @@ void __init files_init(unsigned long mempages)
if (files_stat.max_files < NR_FILE)
files_stat.max_files = NR_FILE;
files_defer_init();
+ lg_lock_init(files_lglock);
percpu_counter_init(&nr_files, 0);
}
diff --git a/fs/super.c b/fs/super.c
index 9674ab2c8718..8819e3a7ff20 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -54,7 +54,22 @@ static struct super_block *alloc_super(struct file_system_type *type)
s = NULL;
goto out;
}
+#ifdef CONFIG_SMP
+ s->s_files = alloc_percpu(struct list_head);
+ if (!s->s_files) {
+ security_sb_free(s);
+ kfree(s);
+ s = NULL;
+ goto out;
+ } else {
+ int i;
+
+ for_each_possible_cpu(i)
+ INIT_LIST_HEAD(per_cpu_ptr(s->s_files, i));
+ }
+#else
INIT_LIST_HEAD(&s->s_files);
+#endif
INIT_LIST_HEAD(&s->s_instances);
INIT_HLIST_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
@@ -108,6 +123,9 @@ out:
*/
static inline void destroy_super(struct super_block *s)
{
+#ifdef CONFIG_SMP
+ free_percpu(s->s_files);
+#endif
security_sb_free(s);
kfree(s->s_subtype);
kfree(s->s_options);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5e65add0f163..76041b614758 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -920,6 +920,9 @@ struct file {
#define f_vfsmnt f_path.mnt
const struct file_operations *f_op;
spinlock_t f_lock; /* f_ep_links, f_flags, no IRQ */
+#ifdef CONFIG_SMP
+ int f_sb_list_cpu;
+#endif
atomic_long_t f_count;
unsigned int f_flags;
fmode_t f_mode;
@@ -1334,7 +1337,11 @@ struct super_block {
struct list_head s_inodes; /* all inodes */
struct hlist_head s_anon; /* anonymous dentries for (nfs) exporting */
+#ifdef CONFIG_SMP
+ struct list_head __percpu *s_files;
+#else
struct list_head s_files;
+#endif
/* s_dentry_lru and s_nr_dentry_unused are protected by dcache_lock */
struct list_head s_dentry_lru; /* unused dentry lru */
int s_nr_dentry_unused; /* # of dentry on lru */

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